Wrench with expanding tip assembly

Abstract

A tool assembly for engaging a head of a fastener. The tool assembly includes an elongated hollow shaft member having a first end and a second end and an actuation rod member moveably disposed within the shaft member. The actuation rod member includes a first end corresponding with the first end of the shaft member and a second end corresponding with the second end of the shaft member and an expandable tip assembly. One end of the expandable tip assembly is movably coupled to the actuation rod. The other end of the expandable tip assembly includes a patterned face. A first contracted state of the expanded tip assembly allows the patterned face to mate with the head of the fastener, and a second expanded state of the expanded tip assembly allows the patterned face to securely engage the head of the fastener.

What is claimed is: 
     
         1 . A tool assembly for engaging a head of a fastener comprising:
 an elongated hollow shaft member having a first end and a second end;   an actuation rod member moveably disposed within the shaft member, the actuation rod member comprising a first end corresponding with the first end of the shaft member and a second end corresponding with the second end of the shaft member; and   an expandable tip assembly, one end of the expandable tip assembly movably coupled to the actuation rod, an other end of the expandable tip assembly having a patterned face, the expandable tip having a first contracted state, wherein the patterned face is configured to mate with the head of the fastener, and a second expanded state, wherein the patterned face is configured to securely engage the head of the fastener.   
     
     
         2 . The tool assembly of  claim 1 , wherein the expandable tip assembly comprises two or more leg members extending longitudinally from the second end of the shaft, the leg members arranged symmetrically around the second end of the actuation rod member, each leg member having a first end and a second end, wherein the first end of each leg member is attached to the second end of the shaft member, the second ends of the leg members form a patterned face that is configured to mate with the head of the fastener. 
     
     
         3 . The tool assembly of  claim 2 , wherein a first movement of the actuation rod member moves the second end of each of the leg members away from a major axis of the shaft member and a second movement of the actuation rod member moves the second end of each of the leg members toward a major axis of the shaft member. 
     
     
         4 . The tool assembly of  claim 2 , wherein the leg members comprise six leg members, and the patterned face formed by the second ends of the leg members is a hexagon. 
     
     
         5 . The tool assembly of  claim 2 , wherein the second end of the actuation rod member comprises a tapered portion, and a threaded portion disposed above the tapered portion;
 the shaft member comprises an inner threaded portion; and   the threaded portion of the actuation rod member is configured to engage the threaded portion of the shaft member such that a rotation of the actuation rod member within the shaft member in a first direction moves the second end of each of the two or more leg members away from a major axis of the shaft member and a rotation of the actuation rod member in a second direction moves the second end of each of the leg members toward a major axis of the shaft member.   
     
     
         6 . The tool assembly of  claim 2 , wherein an inner surface of each of the two or more leg members comprises a taper in operable communication with the tapered portion of the actuation rod member, the taper being configured such that a first longitudinal movement of the actuation rod member moves the second end of each of the two or more leg members away from a major axis of the shaft member and a second longitudinal movement of the actuation rod member moves the second end of each of the leg members toward a major axis of the shaft member. 
     
     
         7 . The tool assembly of  claim 1 , further comprising a first knob attached to the first end of the shaft member and a second knob attached to the first end of the actuation rod member. 
     
     
         8 . The tool assembly of  claim 1 , wherein the two or more leg members comprise a cross section above the second ends of the two or more leg members, the cross section configured to provide a smooth transition between the head of the fastener and the two or more leg members. 
     
     
         9 . The tool assembly of  claim 8 , wherein the shaft member comprises a transition portion, disposed above the second end of the shaft member, the transition portion configured to provide a smooth transition between an outer surface of each of the two or more leg members and the shaft member. 
     
     
         10 . An expandable tip member for a tool assembly for engaging a head of a fastener, the expandable tip member comprising a first end and a second end,
 the first end configured to be attached to the tool assembly, and the second end having a patterned face,   the expandable tip member having a first contracted state, wherein the patterned face is configured to mate with the head of the fastener, and a second expanded state, wherein the patterned face is configured to securely engage the head of the fastener.   
     
     
         11 . The expandable tip member of  claim 10 , wherein the expandable tip further comprises:
 a transition portion disposed below the first end; and   a plurality of leg members extending longitudinally from the transition portion, the plurality of leg members arranged symmetrically around a major axis of the expandable tip member, each leg member having a first end and a second end, wherein the first end of each leg member is attached to the transition portion, and the second ends of the leg members form a patterned face that is configured to mate with the head of the fastener.   
     
     
         12 . The expandable tip member of  claim 11  wherein the transition portion is configured to provide a smooth transition from the tool assembly to the plurality of leg members. 
     
     
         13 . The expandable tip member of  claim 11 , wherein the plurality of leg members comprise six leg members, and the patterned face is a hexagon. 
     
     
         14 . The expandable tip member of  claim 11 , wherein the plurality of leg members comprise a cross section above the second ends of the leg members, the cross section configured to provide a smooth transition between the head of the fastener and the plurality of leg members. 
     
     
         15 . The expandable tip member of  claim 11 , further comprising an actuation rod member having a first end corresponding to the first end of the expandable tip member and a second end disposed within the plurality of leg members,
 the second end of the actuation rod member comprising a tapered portion;   wherein a first movement of the actuation rod member within the expandable tip member moves the second end of each of the plurality of leg members away from a major axis of the expandable tip member and a second movement of the actuation rod member within the expandable tip member moves the second end of each of the plurality of leg members toward the major axis of the expandable tip member.   
     
     
         16 . The expandable tip member of  claim 15 , wherein the actuation rod member further comprises a threaded portion disposed above the tapered portion, and
 the transition portion comprises an inner threaded portion,   wherein the threaded portion of the actuation rod member is configured to engage the inner threaded portion of the transition portion such that a first rotational movement of the actuation rod member within the transition portion moves the second end of each of the plurality of leg members away from a major axis of the expandable tip member and a second rotational movement of the actuation rod member within the transition portion moves the second end of each of the plurality of leg members toward the major axis of the expandable tip member.   
     
     
         17 . The expandable tip member of  claim 15  wherein an inner surface of each of the plurality of leg member comprises a taper in operable communication with the tapered portion of the actuation rod member, and configured such that a first longitudinal movement of the actuation rod member within the expandable tip member moves the second end of each of the plurality of leg members away from a major axis of the expandable tip member and a longitudinal movement of the actuation rod member within the transition portion moves the second end of each of the plurality of leg members toward the major axis of the expandable tip member.